The Primate Supply Information Clearinghouse provides the communication mechanisms needed for efficient sharing of laboratory primates by research investigators and institutions in the United States. The goal is to help reduce the total number of animals needed for research, especially imported primates, by maximizing the use of existing primate resources. The Clearinghouse's conservation and information services include: 1) New Listings, a weekly bulletin listing current needs for and availability of primates, tissues, cadavers, equipment, and services; 2) Continuing Listings, a monthly bulletin for those programs needing to advertise long- term or continuing primate needs or availabilities; and 3) telephone and letter requestors who can be immediately matched or referred to appropriate sources based either on open listings or on a scan of a computerized directory of primate resources. The program services research laboratories, research institutions, zoos, and breeding colonies. Both bulletins are available to investigators and institutions by mail. The overall objectives of the Clearinghouse are to help maximize the use of scarce primate resources, and to reduce the time and effort required by researchers to locate or place animals and tissues. The benefits and necessity of such conservation efforts are increasing daily.